High-rise syndrome in cats

High-rise syndrome (HRS), originally described by Robinson¹, is a term used to refer to cats that fall from two storeys (equivalent to 7m or 23ft) or higher resulting in injury or, less commonly, death².

A variant of HRS has also been recorded in dogs, but is less frequently reported³. While the behaviour of cats is seldom reported in HRS prior to a fall, Whitney and Mehlhaff⁴ and Vnuk et al⁵ state HRS occurs as a result of either cats playing near windows or balconies, chasing insects or birds, or slipping while near windows or balcony railings.

The authors identified a range of retrospective HRS studies and multiple or single case reports, which are reviewed in Table 1^6-14. These studies, generally, were consistent in their findings – such that survival rate is normally above 90%, the average age of the cats tends to be between one and three years old, HRS is not displayed predominantly in either sex, and the most common injuries resulting from HRS are limb fractures, facial injuries, pulmonary contusions and pneumothorax (Table 1).

In addition, Pratschke and Kirby¹⁴ note additional injuries can occur if cats become impaled on fences due to falling from heights. More recently Nakladal et al¹⁵ analysed 73 cases of carpal joint injuries, of which 53 (72.6%) were caused by HRS as a result of falling out of a window – most commonly from the third or fourth floors.

The incidence of this problem remains unknown, but it is likely to be more common than reported and has been suggested to be more prevalent during warmer months in temperate climates, for obvious reasons¹⁵. Time of day has seldom been included in research⁴, but may also be an important factor to consider – particularly in conjunction with seasonal effects.

Younger cats (for example, one to three years of age) may be more susceptible to HRS due to their increased activity and play behaviour, or due to their relative inexperience with hazards, particularly in new or unfamiliar environments^5,16.

In a recent study, Passalacqua and Merola¹⁷ asked 35 owners of cats that had fallen and received veterinary treatment, and 21 owners in a control group, to complete a survey. They found cats of a younger age, and who exhibited aggressive behaviour, were more prone to falling in comparison to the control group¹⁷. As a result, although a small sample size, this suggests falls are often due to inexperience in young cats.

The finding regarding aggression, which is a frequent behavioural issue in cats^18,19 alongside the suggested association of HRS with active and play behaviour⁵, highlights the importance of further research into, and greater consideration of, the effects of temperament and behaviour on HRS.

Breed can also impact on cat behaviour, such that some breeds – for example, Persians – are less active²⁰, while others, such as Siamese, may display breed predispositions towards aggression²¹. Use of breed, behaviour, age and experience-based assessment criteria when determining suitability of cats for adoption or rehoming would be beneficial to reduce the incidence of HRS and, therefore, enhance cat welfare.

In addition to further research into the effects of breed, behaviour and experience on HRS, other topics that are generally not noted or explored in studies of HRS include the substrate on which the cat lands – which could be an important determinant of injuries sustained – and owner-related factors. Greater consideration of how the owner’s general knowledge, education and management of the cat can impact on its susceptibility to HRS would also be of value.

Conclusion

In conclusion, this brief note reviews HRS research to date and highlights areas for further research, as well as considering the application of this research in others to prevent HRS. It has been previously stated that HRS is “100% preventable”²² by following some basic advice for cat owners. This includes:

• keeping windows closed – ensure cats cannot escape from open windows or erect a window screen to ensure a cat does not escape through a window
• remove any furniture that would allow a cat to gain access to an open window
• do not allow cats on to a balcony area unsupervised – especially younger cats

By advising cat owners and potential owners on precautions that should be taken to prevent HRS, as well as factors to consider when choosing cats to reduce susceptibility to HRS (such as age, breed and temperament), veterinary centres may help reduce the incidences and injuries due to HRS seen in practice.